Modern users rely on global navigation satellite system (GNSS)-enabled personal navigation devices (PNDs) or other GNSS-equipped electronic devices such as cell phones to navigate while in motion. Consequently, users require a high degree of accuracy in a wide range of navigation scenarios. However, effective GNSS-based navigation is reduced in areas where signal transmission is hindered, such as parking garages, inside buildings, or in so-called “urban canyons” where, although outdoors, signal transmission is reduced by artificial canyons formed by surrounding buildings.